NEAR FIELD TRANSDUCERs (NFTs) AND METHODS OF FORMING NFTs

ABSTRACT

Devices having an air bearing surface (ABS), the device including a near field transducer, the near field transducer having a peg and a disc, the peg having a region adjacent the ABS, the peg including a plasmonic material selected from gold (Au), silver (Ag), copper (Cu), ruthenium (Ru), rhodium (Rh), aluminum (Al), or combinations thereof; and at least one other secondary atom selected from germanium (Ge), tellurium (Te), aluminum (Al), antimony (Sb), tin (Sn), mercury (Hg), indium (In), zinc (Zn), iron (Fe), copper (Cu), manganese (Mn), silver (Ag), chromium (Cr), cobalt (Co), and combinations thereof, wherein a concentration of the secondary atom is higher at the region of the peg adjacent the ABS than a concentration of the secondary atom throughout the bulk of the peg. Methods of forming NFTs are also disclosed.

PRIORITY

This application claims priority to U.S. Provisional Application No.62/078,096 entitled “NEAR FIELD TRANSDUCERS INCLUDING DOPANTS” filed onNov. 11, 2014, the disclosure of which is incorporated herein byreference thereto.

SUMMARY

Disclosed are devices having an air bearing surface (ABS), the deviceincluding a near field transducer, the near field transducer having apeg and a disc, the peg having a region adjacent the ABS, the pegincluding a plasmonic material selected from gold (Au), silver (Ag),copper (Cu), ruthenium (Ru), rhodium (Rh), aluminum (Al), orcombinations thereof; and at least one other secondary atom selectedfrom germanium (Ge), tellurium (Te), aluminum (Al), antimony (Sb), tin(Sn), mercury (Hg), indium (In), zinc (Zn), iron (Fe), copper (Cu),manganese (Mn), silver (Ag), chromium (Cr), cobalt (Co), andcombinations thereof, wherein a concentration of the secondary atom ishigher at the region of the peg adjacent the ABS than a concentration ofthe secondary atom throughout the bulk of the peg.

Also disclosed are devices that include a light source; a waveguide; anda near field transducer, the near field transducer having a peg and adisc, the peg having a region adjacent the ABS, the peg including aplasmonic material selected from gold (Au), silver (Ag), copper (Cu),ruthenium (Ru), rhodium (Rh), aluminum (Al), or combinations thereof;and at least one other secondary atom selected from germanium (Ge),tellurium (Te), aluminum (Al), antimony (Sb), tin (Sn), mercury (Hg),indium (In), zinc (Zn), iron (Fe), copper (Cu), manganese (Mn), silver(Ag), chromium (Cr), cobalt (Co), and combinations thereof, wherein aconcentration of the secondary atom is higher at the region of the pegadjacent the ABS than a concentration of the secondary atom throughoutthe bulk of the peg and wherein the light source, waveguide and nearfield transducer are configured to transmit light from the light sourceto the waveguide and finally the near field transducer.

Also disclosed are methods of forming a NFT, the method includingforming a structure including plasmonic material and at least onesecondary atom, the at least one secondary atom selected from: germanium(Ge), tellurium (Te), aluminum (Al), antimony (Sb), tin (Sn), mercury(Hg), indium (In), zinc (Zn), iron (Fe), copper (Cu), manganese (Mn),silver (Ag), chromium (Cr), cobalt (Co), and combinations thereof;forming a NFT from the structure including plasmonic material and atleast one secondary atom, the NFT comprising a peg and a disc, the peghaving a region adjacent the ABS; and annealing at least a portion ofthe NFT to affect diffusion of the at least one secondary atom to theregion of the peg adjacent the ABS.

The above summary of the present disclosure is not intended to describeeach disclosed embodiment or every implementation of the presentdisclosure. The description that follows more particularly exemplifiesillustrative embodiments. In several places throughout the application,guidance is provided through lists of examples, which examples can beused in various combinations. In each instance, the recited list servesonly as a representative group and should not be interpreted as anexclusive list.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a pictorial representation of a data storage device in theform of a disc drive that can include a recording head constructed inaccordance with an aspect of this disclosure.

FIG. 2 is a side elevation view of a recording head constructed inaccordance with an aspect of the invention.

FIG. 3 is a schematic representation of a near field transducer.

FIG. 4 is a schematic illustration of a disclosed embodiment of a NFTthat includes a block of secondary atom(s) material.

The figures are not necessarily to scale. Like numbers used in thefigures refer to like components. However, it will be understood thatthe use of a number to refer to a component in a given figure is notintended to limit the component in another figure labeled with the samenumber.

DETAILED DESCRIPTION

Heat assisted magnetic recording (referred to through as HAMR) utilizesradiation, for example from a laser, to heat media to a temperatureabove its curie temperature, enabling magnetic recording. In order todeliver the radiation, e.g., a laser beam, to a small area (on the orderof 20 to 50 nm for example) of the medium, a NFT is utilized. During amagnetic recording operation, the NFT absorbs energy from a laser andfocuses it to a very small area; this can cause the temperature of theNFT to increase. The temperature of the NFT can be elevated up to about400° C. or more.

The very high temperatures that the NFT reaches during operation canlead to diffusion of the material of the NFT (for example gold) from thepeg and towards the disk. In addition, a portion of the NFT may beexposed at the air bearing surface of the recording head and is thussubject to mechanical wearing. NFT performance is greatly influenced bythe heat and mechanical stress during HAMR operation. It would thereforebe advantageous to have NFT devices that are more durable.

Disclosed devices can offer the advantage of providing more efficienttransfer of energy from an energy source to the magnetic storage mediato be heated, a smaller focal point at the point of heating, or somecombination thereof. In some embodiments, disclosed devices can be usedwithin other devices or systems, such as magnetic recording heads, morespecifically, thermally or heat assisted magnetic recording (HAMR)heads, or disc drives that include such devices. Disclosed devices canalso improve or enhance NFT stability by decreasing the rate, amount, orboth of the plasmonic material atoms from the peg tip back towards thedisc.

Disclosed herein are NFTs and devices that include such NFTs. FIG. 1 isa pictorial representation of a data storage device in the form of adisc drive 10 that can utilize disclosed NFTs. The disc drive 10includes a housing 12 (with the upper portion removed and the lowerportion visible in this view) sized and configured to contain thevarious components of the disc drive. The disc drive 10 includes aspindle motor 14 for rotating at least one magnetic storage media 16within the housing. At least one arm 18 is contained within the housing12, with each arm 18 having a first end 20 with a recording head orslider 22, and a second end 24 pivotally mounted on a shaft by a bearing26. An actuator motor 28 is located at the arm's second end 24 forpivoting the arm 18 to position the recording head 22 over a desiredsector or track 27 of the disc 16. The actuator motor 28 is regulated bya controller, which is not shown in this view and is well-known in theart. The storage media may include, for example, continuous media or bitpatterned media.

For heat assisted magnetic recording (HAMR), electromagnetic radiation,for example, visible, infrared or ultraviolet light is directed onto asurface of the data storage media to raise the temperature of alocalized area of the media to facilitate switching of the magnetizationof the area. Recent designs of HAMR recording heads include a thin filmwaveguide on a slider to guide light toward the storage media and a nearfield transducer to focus the light to a spot size smaller than thediffraction limit. While FIG. 1 shows a disc drive, disclosed NFTs canbe utilized in other devices that include a near field transducer.

FIG. 2 is a side elevation view of a recording head that may include adisclosed NFT; the recording head is positioned near a storage media.The recording head 30 includes a substrate 32, a base coat 34 on thesubstrate, a bottom pole 36 on the base coat, and a top pole 38 that ismagnetically coupled to the bottom pole through a yoke or pedestal 40. Awaveguide 42 is positioned between the top and bottom poles. Thewaveguide includes a core layer 44 and cladding layers 46 and 48 onopposite sides of the core layer. A mirror 50 is positioned adjacent toone of the cladding layers. The top pole is a two-piece pole thatincludes a first portion, or pole body 52, having a first end 54 that isspaced from the air bearing surface 56, and a second portion, or slopedpole piece 58, extending from the first portion and tilted in adirection toward the bottom pole. The second portion is structured toinclude an end adjacent to the air bearing surface 56 of the recordinghead, with the end being closer to the waveguide than the first portionof the top pole. A planar coil 60 also extends between the top andbottom poles and around the pedestal. In this example, the top poleserves as a write pole and the bottom pole serves as a return pole.

An insulating material 62 separates the coil turns. In one example, thesubstrate can be AlTiC, the core layer can be Ta₂O₅, and the claddinglayers (and other insulating layers) can be Al₂O₃. A top layer ofinsulating material 63 can be formed on the top pole. A heat sink 64 ispositioned adjacent to the sloped pole piece 58. The heat sink can becomprised of a non-magnetic material, such as for example Au.

As illustrated in FIG. 2, the recording head 30 includes a structure forheating the magnetic storage media 16 proximate to where the write pole58 applies the magnetic write field H to the storage media 16. In thisexample, the media 16 includes a substrate 68, a heat sink layer 70, amagnetic recording layer 72, and a protective layer 74. However, othertypes of media, such as bit patterned media can be used. A magneticfield H produced by current in the coil 60 is used to control thedirection of magnetization of bits 76 in the recording layer of themedia.

The storage media 16 is positioned adjacent to or under the recordinghead 30. The waveguide 42 conducts light from a source 78 ofelectromagnetic radiation, which may be, for example, ultraviolet,infrared, or visible light. The source may be, for example, a laserdiode, or other suitable laser light source for directing a light beam80 toward the waveguide 42. Specific exemplary types of light sources 78can include, for example laser diodes, light emitting diodes (LEDs),edge emitting laser diodes (EELs), vertical cavity surface emittinglasers (VCSELs), and surface emitting diodes. In some embodiments, thelight source can produce energy having a wavelength of 830 nm, forexample. Various techniques that are known for coupling the light beam80 into the waveguide 42 may be used. Once the light beam 80 is coupledinto the waveguide 42, the light propagates through the waveguide 42toward a truncated end of the waveguide 42 that is formed adjacent theair bearing surface (ABS) of the recording head 30. Light exits the endof the waveguide and heats a portion of the media, as the media movesrelative to the recording head as shown by arrow 82. A near-fieldtransducer (NFT) 84 is positioned in or adjacent to the waveguide and ator near the air bearing surface. The heat sink material may be chosensuch that it does not interfere with the resonance of the NFT.

Although the example of FIG. 2 shows a perpendicular magnetic recordinghead and a perpendicular magnetic storage media, it will be appreciatedthat the disclosure may also be used in conjunction with other types ofrecording heads and/or storage media where it may be desirable toconcentrate light to a small spot.

FIG. 3 is a schematic view of a NFT 90 in combination with an optionalheat sink 92. The NFT includes a disk shaped portion 94 and a peg 96extending from the disk shaped portion. The heat sink 92 can bepositioned between the disk shaped portion and the sloped portion of thetop pole in FIG. 2. When mounted in a recording head, the peg may beexposed at the ABS and thus can be subjected to mechanical wearing. Thesurface 98 of the peg 96 will be exposed at the ABS when included in arecording head.

Possible explanations for recession of the peg (away from the ABSsurface 98) can include void nucleation via vacancy/effect condensationat the peg tip due to the excessive power density and temperature and/ortopographic flaws (e.g., grain boundaries, head overcoatsteps/scratches, etc.) and void growth inward (e.g., atoms, for examplegold atoms) move away from the peg tip and vacancies move towards thepeg tip. The second mechanism may be facilitated by rapid plasmonicmaterial (e.g., gold)/oxide (head overcoat) interface diffusion. Onemethod of reducing or diminishing the effect of interface diffusion isto use metal adhesives at the plasmonic material/oxide interfaces toeliminate or minimize interface diffusion paths. The interface at thesurface 98, where the interface is formed by the peg and an overlyinghead overcoat (not shown in FIG. 3). If the metal adhesive is to beutilized at the plasmonic material/head overcoat interface, the metaladhesive region needs to be limited to the peg tip region in order toavoid electrically shunting the reader. Thus, an area selective methodwould be needed to form the adhesive region at the peg-tip/head overcoatinterface. This is challenging utilizing traditional processes andtherefore additional methods of affecting the recession mechanisms arenecessary.

Disclosed herein are methods of preventing or minimizing plasmonicmaterial atoms, vacancies, or both from migrating within the peg andespecially the peg tip. Furthermore, methods of relatively easily (froma processing standpoint) forming an adhesive layer at the peg tip/headovercoat interface are also disclosed. In prior NFTs, plasmonic atomvacancies diffuse towards the tip of the peg, which is thought to leadto recession and likely failure of the NFT and head. Disclosed NFTsinclude a metal with relatively high diffusivity in the plasmonicmaterial, for example a diffusivity that is higher in the plasmonicmaterial than that of the plasmonic material in itself. In this way, themetal diffuses to the tip of the peg. This may provide various benefits,including, for example: preventing or minimizing plasmonic materialatoms and/or vacancies from migrating in order to stop void growth atthe peg tip and thus make the NFT structure more stable; providingadhesion between the plasmonic material and the head overcoat (e.g., theadhesive metals will be self-aligned with the peg tip so there is norisk of reader shunting) via a relatively easy process (e.g., easierthan patterning at the ABS); preventing or cutting off the diffusionpath by forming an oxide at the peg tip (the metallic portion or thesub-oxide portion of the metallic oxide will still provide adhesionbenefit); combinations thereof.

The particular atom(s) to be added into the plasmonic material can bechosen based on various properties. For example, the diffusivity of themetal in the plasmonic material can be compared to the self-diffusivityof the plasmonic material. In some embodiments, metals that can be addedto plasmonic materials can have a diffusivity in that material that isat least equal to or greater than the self-diffusivity of the plasmonicmaterial. In some embodiments, metals that can be added to plasmonicmaterials can have a diffusivity in that material that is greater thanthe self-diffusivity of the plasmonic material. In some embodiments,metals that can be added to plasmonic materials can have a diffusivityin that material that is substantially greater than the self-diffusivityof the plasmonic material.

As an example, assuming that the plasmonic material is gold (Au), Table1 below provides diffusivity of various metals, including gold, in gold.

TABLE 1 Diffusivity in Au Metal (@ 900-1300 K (10⁻¹² m²/s) Ge 16.4 Te 16Al 12.7 Sb 10 Sn 10 Hg 8.9 In 7.4 Zn 5.4 Fe 3.4 Cu 2.7 Mn 2.6 Ag 2 Cr1.7 Co 1.4 Au 1.3 Ni 1 V 0.64 Ti 0.35 Zr 0.2 Pd 0.18 Pt 0.13 Hf 0.075

As seen from Table 1, the following metals may be useful in combinationwith gold to provide advantages such as those discussed above becausethey have a diffusivity in gold that is higher than the self-diffusivityof gold: germanium (Ge), tellurium (Te), aluminum (Al), antimony (Sb),tin (Sn), mercury (Hg), indium (In), zinc (Zn), iron (Fe), copper (Cu),manganese (Mn), silver (Ag), chromium (Cr), cobalt (Co), andcombinations thereof.

Other properties that may be considered, in place of diffusivity or inaddition to diffusivity can include, for example the enthalpy ofsegregation (H_(seg)), the solid solubility in the plasmonic material,and the Gibbs free energy of the formation of the oxide (to indicate thetendency of segregation) for example.

In some embodiments, secondary atoms that may be utilized can include,for example germanium (Ge), tellurium (Te), aluminum (Al), antimony(Sb), tin (Sn), mercury (Hg), indium (In), zinc (Zn), iron (Fe), copper(Cu), manganese (Mn), silver (Ag), chromium (Cr), cobalt (Co), andcombinations thereof. In some embodiments, secondary atoms that may beutilized can include, for example germanium (Ge), aluminum (Al),antimony (Sb), zinc (Zn), iron (Fe), copper (Cu), manganese (Mn), silver(Ag), chromium (Cr), cobalt (Co), or combinations thereof. In someembodiments, secondary atoms that may be utilized can include, forexample iron (Fe), cobalt (Co), germanium (Ge), aluminum (Al), antimony(Sb), or combinations thereof. In some embodiments, secondary atoms thatmay be utilized can include, for example mercury (Hg).

In some embodiments, it may be advantageous to prevent or minimizesegregation and accumulation at NFT/oxide interfaces other than the ABS(e.g., the top, bottom and sides of peg) as it might reduce the benefitof segregation to the peg tip, cause higher optical penalty by adding anoptically lossy material around the NFT, or combinations thereof.Different lattice planes (e.g., Au lattice planes) have differentsurface energies. As such, deposition of the plasmonic material could beconfigured to form a (111) oriented peg. The top and the bottom of thepeg could be (111) oriented, which would give them a relatively lowsurface energy (e.g., Au orientation (111)—surface energy 1.28 J/m²;(100)—surface energy 1.63 J/m²; and (110) surface energy 1.70 J/m²). Themetal that is added to the plasmonic material would be energeticallyfavored to segregate to the tip of the peg (non-(111) oriented) in orderto lower the overall surface energy of the system.

Disclosed NFTs may be made of a primary atom and at least one secondaryatom. In some embodiments, the primary atom may have a higher atomicpercentage (at %) in the NFT. In some embodiments, the primary atom maybe gold (Au). Alternatively, the primary atom may be some other materialthat has plasmonic properties. For example, the primary atom may besilver (Ag), copper (Cu), aluminum (Al), rhodium (Rh), or ruthenium (Ru)for example. In some embodiments, more than one secondary atom isincluded in a NFT. A secondary atom(s) may be chosen by considering oneor more properties of the primary atom and potential secondary atoms.Illustrative properties can include, for example diffusivity of thesecondary atom in the primary atom, diffusivity of the secondary atom inthe primary atom versus self-diffusion of the primary atom, orcombinations thereof.

Generally, a NFT can include a primary atom and at least one secondaryatom. In some embodiments, the secondary atom(s) can have an atomicpercent (at %) that is not greater than 50 at %, in some embodiments,not greater than 30 at %, in some embodiments, not greater than 5 at %,and in some embodiments, not greater than 1 at %. In some embodiments,the amount of the secondary atom can be not greater than 100 pm (0.01 at%), in some embodiments not greater than 5 at %, or in some embodimentsnot greater than 10 at %. In some embodiments, the amount of thesecondary atom can be not less than 10 ppm (0.001 at %), in someembodiments not less than 50 ppm (0.005 at %), or in some embodimentsnot less than 100 ppm (0.01 at %). In some embodiments, the amount ofthe secondary atom can be chosen so that a desired thickness of thesecondary atom at the peg is formed once annealing has been performed.

Various methods and processes can be utilized herein to form NFTs thatinclude a plasmonic material and a secondary atom such as thoseillustrated above. One such method can include the following steps.First, the plasmonic material and the metal is co-sputtered (either froma single composite target or two separate targets) to form an alloy ofthe two. The NFT structure can then be formed using known patterning andformation methods typically utilized in wafer processing. A heattreatment can be applied to the structure at this point. Once the NFThas been formed (and optionally heat treated), a head overcoat (HOC) canbe deposited and the air bearing surface (ABS) can be formed usingtypically utilized wafer processing methods. NFT (and the HOC) can beheat treated at this point (whether it has or has not already been heattreated). The heat treatment (at either or both points in the process)is designed to cause the secondary atom (e.g., the metal) in the alloymaking up the NFT to diffuse to the peg tip. The annealing can includean annealing step that is specifically designed to affect thisdiffusion, it can be done through the operation of the HAMR head itselfas it heats up when utilized, or combinations thereof.

Another method includes forming a multilayer structure including layersof the plasmonic material alternating with layers of the secondary atom(e.g., the metal). In some embodiments, the layers of secondary atomscan be thinner, in some embodiments significantly thinner than thelayers of plasmonic material Thinner layers of secondary atoms allowonly the desired amount of secondary atom in the final “total” ofmaterial (e.g., plasmonic material plus secondary atom). The NFTstructure can then be formed using known patterning and formationmethods typically utilized in wafer processing. A heat treatment can beapplied to the structure at this point. Once the NFT has been formed(and optionally heat treated), a head overcoat (HOC) can be depositedand the air bearing surface (ABS) can be formed using typically utilizedwafer processing methods. NFT (and the HOC) can be heat treated at thispoint (whether it has or has not already been heat treated). The heattreatment is designed to cause the secondary atom (e.g., the metal) fromthe multilayer structure making up the NFT to diffuse to the peg tip.The annealing can include an annealing step that is specificallydesigned to affect this diffusion, it can be done through the operationof the HAMR head itself as it heats up when utilized, or combinationsthereof. Multilayer structures can be advantageous for facilitatingdiffusion because diffusion is more likely to occur and/or quicker atinterfaces than it is in the bulk of a material. Therefore, by formingmore interfaces (each layer of metal and adjacent layer of plasmonicmaterial forms an interface), diffusion of the metal to the peg tip canbe facilitated, increased, sped up, or any combination thereof.

Another method combines formation of one or more co-sputtered alloylayers with a multilayer structure including distinct layers ofplasmonic material and metal. In some embodiments, a specificillustrative overall structure that could be formed in a NFT can includethe following layers: plasmonic material layer (e.g., 5 nm)/plasmonicmaterial-secondary atom co-sputtered alloy layer (e.g., 2% secondaryatom, total thickness 5 nm)/plasmonic material layer (e.g., 2nm)/secondary atom layer (e.g., 1 nm)/plasmonic material layer (e.g., 2nm)/plasmonic material-secondary atom co-sputtered alloy layer (e.g., 2%secondary atom, total thickness 5 nm)/plasmonic material layer (e.g., 2nm). The total thickness of this illustrative structure would be about25 nm. It should be noted however, that structures including otherspecific materials could have different thicknesses. For example, amultilayer structure that includes rhodium (Rh) as the plasmonicmaterial could have a thickness of about 45 nm. Such a structure couldtake advantage of both grain boundary and bulk diffusion offered by theco-sputtered alloy layers and interface diffusion offered by themultiple interfaces to facilitate, speed up, increase, or combinationsthereof diffusion to the peg tip.

Another method includes formation of a block of the secondary atom. FIG.4 illustrates a possible embodiment of such a structure. As seen in FIG.4, the peg 110 has its front at the ABS, 105 and has an opposing backregion 113. Located behind the peg 110 is the disc/heat sink 115. Thepeg and the disc/heat sink function together to gather energy inputtherein and focus it, via the peg 110 to obtain a smaller spot of energywhich is then output to associated magnetic media. Adjacent the backregion 113 of the peg 110 is a block 120. The block 120 can generally bedescribed as being positioned between the peg 110 and the disc/heat sink115. The block 120 is made of one or more than one of the secondaryatoms discussed above. Once the structure depicted in FIG. 4 has beenformed (through known patterning and formation methods typicallyutilized in wafer processing) a HOC is deposited on the front of the pegand the ABS, 105 is formed through regular slider processing. Then, aheat treatment can be applied to the structure. It should also be notedthat the heat treatment can be done before (or both before and after)the HOC is deposited. The heat treatment is designed to cause thesecondary atom (e.g., the metal) from the block 120 to diffuse to thepeg tip. The annealing can include an annealing step that isspecifically designed to affect this diffusion, it can be done throughthe operation of the HAMR head itself as it heats up when utilized, orcombinations thereof. In some embodiments, the addition of a block (suchas that depicted in FIG. 4) can be utilized with co-sputtered alloys,multilayer structures or combinations thereof.

Any combination of various methods/structures disclosed herein can beutilized in order to affect diffusion of a secondary atom(s) to the tipof the peg. All (or combinations thereof) of these structures and/orformation processes are designed to drive the secondary atom towards thetip of the peg in order to prevent or minimize plasmonic material atomsand/or vacancies from migrating in order to stop void growth at the pegtip and thus make the NFT structure more stable; prevent or cut off thediffusion path by forming an oxide at the peg tip; or combinationsthereof.

In some embodiments, methods, structures, or combinations thereof can beutilized to concentrate the secondary atom(s) in a region of the pegadjacent the ABS. In some embodiments, disclosed NFTs include a pegwhere the concentration of the secondary atom is higher at a region ofthe peg adjacent the ABS than the concentration of the secondary atom isthroughout the bulk of the peg. In some embodiments, methods,structures, or combinations thereof can be utilized to concentrate thesecondary atom(s) in the first 2 nm of the peg at the ABS, the first 5nm of the peg at the ABS, or the first 10 nm of the peg at the ABS. Insome embodiments, the first 2 nm (first 5 nm, or first 10 nm) of the pegat the ABS will have a higher concentration of secondary atom(s) thanthe remaining portions of the peg. The concentration of the secondaryatom(s) in various regions of the peg can be detected and quantifiedusing known techniques, including for example chemical mappingtechniques that have spatial resolution, including for example energydispersive X-ray spectroscopy (EDX) analysis, transmission electronmicroscopy (TEM), and electron energy loss spectroscopy (EELS).Alternatively, chemical line scans can be done using similar techniquesand measurement devices.

Any of the methods of affecting diffusion of the secondary atom to thetip of the peg can also be combined with an optional step of oxidizingsome of the secondary atom(s) at the peg tip. The optional oxidationstep can be affected using any known methods of oxidation, including forexample annealing in an environment containing oxygen (O2), air, orother oxygen containing gases. Depending on the technique, the oxygenaffinity of the secondary atom can also be considered. Oxidation of aportion of the secondary atoms, e.g., the secondary atoms that havediffused all the way to the front few monolayers of the peg couldprovide additional adhesion benefits for maintaining adhesion betweenthe peg and the overlying overcoat. In some embodiments, this oxidationstep can occur before the head overcoat is deposited at the ABS. Forminga layer of oxide at the tip of the peg in this way would be much morelikely to better align the oxidized material with the peg because thematerial being oxidized would be coming out of the peg itself. As such,it could be advantageous in comparison to a method of patterning anoxide layer on the surface of the peg.

All scientific and technical terms used herein have meanings commonlyused in the art unless otherwise specified. The definitions providedherein are to facilitate understanding of certain terms used frequentlyherein and are not meant to limit the scope of the present disclosure.

As used in this specification and the appended claims, “top” and“bottom” (or other terms like “upper” and “lower”) are utilized strictlyfor relative descriptions and do not imply any overall orientation ofthe article in which the described element is located.

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” encompass embodiments having pluralreferents, unless the content clearly dictates otherwise.

As used in this specification and the appended claims, the term “or” isgenerally employed in its sense including “and/or” unless the contentclearly dictates otherwise. The term “and/or” means one or all of thelisted elements or a combination of any two or more of the listedelements.

As used herein, “have”, “having”, “include”, “including”, “comprise”,“comprising” or the like are used in their open ended sense, andgenerally mean “including, but not limited to”. It will be understoodthat “consisting essentially of”, “consisting of”, and the like aresubsumed in “comprising” and the like. For example, a conductive tracethat “comprises” silver may be a conductive trace that “consists of”silver or that “consists essentially of” silver.

As used herein, “consisting essentially of,” as it relates to acomposition, apparatus, system, method or the like, means that thecomponents of the composition, apparatus, system, method or the like arelimited to the enumerated components and any other components that donot materially affect the basic and novel characteristic(s) of thecomposition, apparatus, system, method or the like.

The words “preferred” and “preferably” refer to embodiments that mayafford certain benefits, under certain circumstances. However, otherembodiments may also be preferred, under the same or othercircumstances. Furthermore, the recitation of one or more preferredembodiments does not imply that other embodiments are not useful, and isnot intended to exclude other embodiments from the scope of thedisclosure, including the claims.

Also herein, the recitations of numerical ranges by endpoints includeall numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2,2.75, 3, 3.80, 4, 5, etc. or 10 or less includes 10, 9.4, 7.6, 5, 4.3,2.9, 1.62, 0.3, etc.). Where a range of values is “up to” a particularvalue, that value is included within the range.

Use of “first,” “second,” etc. in the description above and the claimsthat follow is not intended to necessarily indicate that the enumeratednumber of objects are present. For example, a “second” substrate ismerely intended to differentiate from another infusion device (such as a“first” substrate). Use of “first,” “second,” etc. in the descriptionabove and the claims that follow is also not necessarily intended toindicate that one comes earlier in time than the other.

Thus, embodiments of near field transducers (NFTs) and methods offorming NFTs are disclosed. The implementations described above andother implementations are within the scope of the following claims. Oneskilled in the art will appreciate that the present disclosure can bepracticed with embodiments other than those disclosed. The disclosedembodiments are presented for purposes of illustration and notlimitation.

What is claimed is:
 1. A device having an air bearing surface (ABS), thedevice comprising: a near field transducer, the near field transducercomprising a peg and a disc, the peg having a region adjacent the ABS,the peg comprising: a plasmonic material selected from gold (Au), silver(Ag), copper (Cu), ruthenium (Ru), rhodium (Rh), aluminum (Al), orcombinations thereof; and and at least one other secondary atom selectedfrom germanium (Ge), tellurium (Te), aluminum (Al), antimony (Sb), tin(Sn), mercury (Hg), indium (In), zinc (Zn), iron (Fe), copper (Cu),manganese (Mn), silver (Ag), chromium (Cr), cobalt (Co), andcombinations thereof, wherein a concentration of the secondary atom ishigher at the region of the peg adjacent the ABS than a concentration ofthe secondary atom throughout the bulk of the peg.
 2. The deviceaccording to claim 1, wherein the plasmonic material is gold (Au). 3.The device according to claim 1, wherein the at least one secondary atomis selected from: germanium (Ge), aluminum (Al), antimony (Sb), zinc(Zn), iron (Fe), copper (Cu), manganese (Mn), silver (Ag), chromium(Cr), cobalt (Co), or combinations thereof.
 4. The device according toclaim 1, wherein the at least one secondary atom is selected from: iron(Fe), cobalt (Co), germanium (Ge), aluminum (Al), antimony, orcombinations thereof.
 5. The device according to claim 1, wherein the atleast one secondary atom is selected from mercury (Hg).
 6. The deviceaccording to claim 1, wherein the NFT comprises a multilayer structureof alternating plasmonic material layers and secondary atom layers. 7.The device according to claim 1, wherein the NFT comprises an alloy ofplasmonic material and secondary atom.
 8. The device according to claim1, wherein the peg comprises a back region opposite the ABS adjacentregion and the device further comprises a block comprising the at leastone secondary atom adjacent the back region of the peg.
 9. The deviceaccording to claim 1, wherein the NFT comprises about 0.1 atomic percentto about 5 atomic percent of the at least one secondary atom.
 10. Theapparatus according to claim 1 further comprising an energy source. 11.A device comprising: a light source; a waveguide; and a near fieldtransducer, the near field transducer comprising a peg and a disc, thepeg having a region adjacent the ABS, the peg comprising: a plasmonicmaterial selected from gold (Au), silver (Ag), copper (Cu), ruthenium(Ru), rhodium (Rh), aluminum (Al), or combinations thereof; and and atleast one other secondary atom selected from germanium (Ge), tellurium(Te), aluminum (Al), antimony (Sb), tin (Sn), mercury (Hg), indium (In),zinc (Zn), iron (Fe), copper (Cu), manganese (Mn), silver (Ag), chromium(Cr), cobalt (Co), and combinations thereof, wherein a concentration ofthe secondary atom is higher at the region of the peg adjacent the ABSthan a concentration of the secondary atom throughout the bulk of thepeg and wherein the light source, waveguide and near field transducerare configured to transmit light from the light source to the waveguideand finally the near field transducer.
 12. The device according to claim11, wherein the plasmonic material is gold (Au).
 13. The deviceaccording to claim 11, germanium (Ge), aluminum (Al), antimony (Sb),zinc (Zn), iron (Fe), copper (Cu), manganese (Mn), silver (Ag), chromium(Cr), cobalt (Co), or combinations thereof.
 14. The device according toclaim 11, wherein the at least one secondary atom is selected frommercury (Hg).
 15. A method of forming a NFT comprising: forming astructure comprising plasmonic material and at least one secondary atom,the at least one secondary atom selected from: germanium (Ge), tellurium(Te), aluminum (Al), antimony (Sb), tin (Sn), mercury (Hg), indium (In),zinc (Zn), iron (Fe), copper (Cu), manganese (Mn), silver (Ag), chromium(Cr), cobalt (Co), and combinations thereof; forming a NFT from thestructure comprising plasmonic material and at least one secondary atom,the NFT comprising a peg and a disc, the peg having a region adjacentthe ABS; and annealing at least a portion of the NFT to affect diffusionof the at least one secondary atom to the region of the peg adjacent theABS.
 16. The method according to claim 15, wherein forming the structurecomprises forming a multilayer structure comprising sublayers ofplasmonic material and sublayers of secondary atom(s).
 17. The methodaccording to claim 15, wherein forming the structure comprisesco-sputtering the plasmonic material and the secondary atom to form analloy of the plasmonic material and the secondary atom.
 18. The methodaccording to claim 15, wherein forming the structure comprises forming amultilayer structure comprising sublayers of plasmonic material andsublayers of secondary atom(s) and co-sputtering the plasmonic materialand the secondary atom to form an alloy layer of the plasmonic materialand the secondary atom.
 19. The method according to claim 15 furthercomprising forming a head overcoat layer on the ABS.
 20. The methodaccording to claim 19, wherein the step of annealing is done before thehead overcoat layer is deposited on the ABS.